Climate Change Chart of Monterrey, Mexico

Overview of climate changes

Changes in sunshine duration

Mean daily sunshine duration, averaged across calendar months, had an unweighted difference of -0.45 hours/day compared with the earlier reference period. This describes the aggregate of monthly means, not a change shared by every month. Monthly differences varied: the largest decrease was in November, at -1.31 hours/day, while February recorded the largest increase, with a difference of +0.14 hours/day. These are differences in mean daily sunshine hours, not measures of total sunshine for an entire month.

Changes in rainfall

Averaged across calendar months, mean daily rainfall had an unweighted difference of +0.05 mm/day compared with the earlier reference period. This small aggregate increase does not mean that rainfall rose in every month, and these are daily means rather than monthly totals. The largest monthly increase in mean daily rainfall occurred in September, at +1.28 mm/day. By contrast, August had the largest monthly decrease, a difference of -0.89 mm/day, showing that the monthly changes were not all in the same direction.

Temperature changes

The unweighted mean difference across calendar-month temperature means was an increase of +0.98 °C compared with the earlier reference period; this summarizes the set of monthly means, rather than describing every month or daytime maximum temperatures. The largest monthly increase was in March, with a difference of +1.64 °C. This identifies the strongest monthly increase, not a uniform change throughout the year.

Changes in snowfall

Across calendar months, the unweighted mean difference in mean daily snowfall was a decrease of -0.01 mm/day. The averages are displayed at limited precision, so a small difference should not be taken to mean snowfall was absent or unchanged beyond that precision. The largest monthly decrease in mean daily snowfall was in January, with a difference of -0.13 mm/day; the largest monthly increase was in December, at +0.05 mm/day. These daily-mean differences describe particular months, not monthly snowfall totals.